A preparative and solution study of a modified β-cyclodextrin and its europium(III) complex, and their interactions with racemic amino acid anions

Abstract

<jats:p> The synthesis and characterization of 6A-deoxy-6A-(1,4,7-tri(carboxylatomethyl)-1,4,7,10-tetraazacyclododecan-10-yl)-β-cyclodextrin (1b) are reported. A fluorescence lifetime study of its Eu3+ complex (1c) is consistent with one water coordinating Eu3+ in addition to hepta-coordination by (1b). 1H NMR studies are consistent with (1b) forming host–guest complexes with (R/S)-histidinate (2a), (R/S)-tyrosinate (2b), (R/S)-phenylalaninate (2c), and (R/S)-tryptophanate (2d), with enantioselectivity shown for (2b). Similar studies are consistent with (1c) complexing (2a–d), with enantioselectivity shown for (2a).</jats:p>